2005 350z with Vortech tuned to 430 HP / 380 tq
bigger injectors, plenum spacer, 3.12 pulley, tuned by Osirus.

Been problem free for a year now, aside from a few very minor issues.
Most i do is **** off STi's and the occasional 335i that "assume" i'm stock...

Lately, when driving around, say on teh freeway at 65, I grab 4th and punch it, and the car cuts power, like it lost traction.
It will also do this if I grab 2nd or 3rd, starting from around 40.

The slip light does not come on.
It' didnt do this for the first 9 months, and has gotten worse, but doesnt do it every time.

Leaning towards needing new plugs.
Current Plugs are Greddy L9, and have 10 k on them now, after a year of use.
Fuel pump is a wahlbro 255.

Thoughts?

the plugs are 25-30 a piece, so i dont want to replace unless it is needed... I have not pulled any yet.

I do need to clean the air filter (ordered a new one)

belt is not slipping.

 

VDC Will cut power without the Slip light coming on.....

Is this happening with VDC ON or OFF?

I'm assuming OFF, because you said light did not come on...

If so, Drive with VDC OFF and see what happens.

 

I'm pretty sure i did, but I will try it again.

Not exactly excited about the engine cutting power at 65, reved to 4500...

I'll report back...

I will probably pull a few easy to reach plugs tomorrow when I change the oil.

 

so the rpms went up but the power died off?

if so then i would say the oem clutch is toast with that supercharger.

 

not sure where you are getting your spark plugs but it's 45$ for a complete SET of iridiums. Coppers are only about 30$ a set.

 

If you have a cipher cable take some logs and post them up. Or at least a video. Hard to tell anything from such a vague description of the issue.

 

Greddy L9's

greddy pn 13000169

 

RPM's dont rise, it's a sudden loss of power, motor gets "quiet"

clutch is upgraded, with a light flywheel.

 

I sent an email off to my tuner in town.
I think they are moving their shop this week, so I dont expect to hear back right away.

I'll go for a cruise tomorrow and try to re-produce the issue.

 

What temp plugs did you run with your water injection?
I'm thinking about it and oem spec plugs might not be a bad idea with 100% water injection.

IMHO man, don't drive the car unless you have to. I'd spend the time you would cruising wrenching away and checking those spark plugs.
I know that's a bit over-kill, and it's likely not that bad but I'd still play it safe. Take care of that oem block, avoid building it for a stupid little decision.

 

I have replaced quite a few Throttle bodies on F/I cars with that same issue you are having....

 

have you checked the MAF sensor? I had a similar problem, just upgraded it to PMAS HPX and the problem was solved....

 

^^^ thats true... i didn't see an upgraded MAF on your list of mods. We usually see the MAFs max out around 375whp with the Vortech kits

 

Check to make sure your maf didn't come loose. Unplug it then plug it back in. Reset your ecu. I had a similar problem

 

im running 1 step colder with meth and water injection and its still not cold enough, preigniting up top in the rpms around 6k+ so i wouldnt try stock range plugs. i need to order some 2 step colder but i cant seem to locate any >.>

 

hes refering to denso's not greddy's alot cheaper and more or less the same plug they just dont make a 2 step colder than stock

 

I run 1 step colder platinums. I said copper earlier but i meant platinums. I think they cost around 6$ each. 650hp engine.

I spend less on the platinums but i change my plugs more often. I don't care how long iridiums last on a stock engine. in my built engine they will get changed just as often as i would with my platinums so it makes no sense to buy the more expensive ones.

I get mine from summitracing

 

I was planning on buying a few sets and changing them out every oil change (just to keep tabs on how its running), alongside a full oil filter inspection every change.

I was more talking about just the straight up temperature, with water the chamber is running a lot cooler so you could actually pick up some power by burning a little hotter...

Ace, thats with a 50/50 mix? I think with a 100% water injection there is a huge difference in latent heat potential so I'm not sure how that compares, but I'll go with the tried and true 2 steps.

Or I'll go with gtr plugs (if I can find them at an affordable rate, probably will stick with cheapos though, LOL I have a huge parts list saved from summit including plugs, they're the best lol!)

 

Ya I'm just running 50/50

 

If you are pre-igniting then you need to adjust the timing.

1 step colder should have no issue on it as there are people running no injection at all with straight race gas into the 800hp range without any issues. They don't have any water or meth to cool down with straight race gas and they aren't having issues.

I'm running e85 which is a lot cooler than pump but 650hp on 1 step colder plugs with no issues at all. I was mid 500hp on 93 octane without any signs of detonation or preignition with 1 step colder as well.

Unless you are never going to drive it on the street i probably wouldn't use 2 step colder plugs. They will foul quite a bit easier under normal driving. That and there isn't a proven reason why until you are up around 1000hp and never drive it around under vac map (ie, track car only).